US4066453A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of printing forms
Assignee: Hoechst AG
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Filing: 1976-06-02
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Granted: 1978-01-03
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Expires: 1996-06-02
Abstract
Abstract This invention relates to an improvement in the process for the preparation of printing forms or metallic etchings from electrophotographic or electrographic reproduction materials composed of a support with a photoconductive or high-ohmic layer thereon, by charging and image-wise exposure, or by image-wise charging, development of the electrostatic image with a finely-divided toner, fixing, and removal of the layer in the image-free areas by means of a decoating solution, the improvement comprising developing the electrostatic image with a developer which reacts at least superficially with the image areas at room temperature, thereby simultaneously effecting development and resistance to the decoating solution, or developing the electrostatic image with a developer which reacts with the decoating solution and thereby deactivates it in the image areas.
Inventors
- 👤 Erwin Lind
- 👤 Franz Freimuth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:10
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/26; G03G13/28; G03G13/32; G03G9/00; G03G9/08; G03G9/09; G03G9/0926; G03G9/097; G03G9/09708; G03G9/09733; G03G9/09758; G03G9/09775; G03G9/09783; G03G9/09791
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
131 words
In the process for the preparation of printing forms or metallic etchings from electrophotographic or electrographic reproduction materials composed of a support with a photoconductive organic or high-ohmic organic layer thereon, by charging and imagewise exposure, or by imagewise charging, development of the electrostatic image with a finely divided toner, fixing, and removal of the layer in the image-free areas by means of a decoating solution, the improvement which ccomprises developing the electrostatic image with a developer which chemically reacts at least superfically with the image areas of the photoconductive organic or high-ohmic organic layer at room temperature, thereby simultaneously effecting development and resistance to the decoating solution, or developing the electrostatic image with a developer which chemically reacts with the decoating solution and thereby deactivates it in the image areas.
Claim 2
Dependent Claim
131 words
In the process for the preparation of printing forms or metallic etchings from electrophotographic or electrographic reproduction materials composed of a support with a photoconductive organic or high-ohmic organic layer thereon, by charging and imagewise exposure, or by imagewise charging, development of the electrostatic image with a finely divided toner, fixing, and removal of the layer in the image-free areas by means of a decoating solution, the improvement which ccomprises developing the electrostatic image with a developer which chemically reacts at least superfically with the image areas of the photoconductive organic or high-ohmic organic layer at room temperature, thereby simultaneously effecting development and resistance to the decoating solution, or developing the electrostatic image with a developer which chemically reacts with the decoating solution and thereby deactivates it in the image areas.
Claim 3
Dependent Claim
35 words
A process according to claim 1 in which the developer reacts at least partially with a resin binder of the photoconductive or highohmic layer to form a complex compound, a chelate compound, or a salt.
Claim 4
Dependent Claim
28 words
A process according to claim 1 in which the developer reacts at least partially with the photoconductor component of the layer to form a sparingly soluble donor-acceptor complex.
Claim 5
Dependent Claim
46 words
A process according to claim 1 in which the developer reacts at least partially with a component of the decoating solution to form a salt and thereby prevents the decoating solution from acting upon the areas of the copying layer which are covered by the developer.
Claim 6
Dependent Claim
24 words
A process according to claim 1 in which the developer is composed of a high-ohmic liquid phase with a finely-divided solid phase dispersed therein.
Claim 7
Dependent Claim
44 words
A process according to claim 1 in which the developer contains at least one salt of a multi-valent metal, said salt reacting with a polymer or a copolymer containing acid groups or anhydride groups which is present in the layer as a resin binder.
Claim 8
Dependent Claim
13 words
A process according to claim 1 in which the developer comprises magnesium sulfate.
Claim 9
Dependent Claim
14 words
A process according to claim 1 in which the developer comprises potassium aluminum sulfate.
Claim 10
Dependent Claim
13 words
A process according to claim 1 in which the developer conprises copper chloride.
Claim 11
Dependent Claim
21 words
A process according to claim 1 in which the developer comprises at least one compound of the triphenyl methane dyestuff type.
Claim 12
Dependent Claim
17 words
A process according to claim 1 in which the developer comprises at least one aromatic diazonium salt.
Claim 13
Dependent Claim
35 words
A process according to claim 1 in which the developer comprises at least one substance which serves as an electron acceptor or electron donor in molecular complexes formed with the photoconductor present in the layer.
Claim 14
Dependent Claim
40 words
A process according to claim 12 in which the developer, being an electron acceptor, comprises at least one compound selected from the group consisting of tetraphenyl cyclopentadienone, benzoquinone, dicyanochloro benzoquinone, benzoanthraquinone, tetrachloroquinone, dibromosuccinic acid, tetrachlorophthalic anhydride, dinitronaphthalic anhydride and tetranitronaphthalene.
Claim 15
Dependent Claim
13 words
A process according to claim 13 in which the developer comprises tetraphenyl cyclopentadienone.
Claim 16
Dependent Claim
13 words
A process according to claim 1 in which the developer comprises calcium oxide.
Claim 17
Dependent Claim
17 words
A process according to claim 1 in which the developer comprises boric acid or toluene sulfonic acid.
Claim 18
Dependent Claim
22 words
A process according to claim 1 in which the developer additionally contains a finely-divided solid substance which renders the image areas hydrophobic.
Claim 19
Dependent Claim
24 words
A process according to claim 17 in which the substance imparting hydrophobic properties is selected from the group consisting of bitumen, waxes, and resins.
Claim 20
Dependent Claim
26 words
A process according to claim 1 in which the photoconductive or high-ohmic layer contains a resin binder which is soluble in aqueous or alcoholic solvent systems.
Claim 21
Dependent Claim
25 words
A process according to claim 19 in which the resin binders used are composed of high molecular weight substances containing groups which render them alkali-soluble.
Claim 22
Dependent Claim
17 words
A process according to claim 19 in which the resin binder is a copolymer containing anhydride groups.
Claim 23
Dependent Claim
16 words
A process according to claim 19 in which the resin binder is a styrene/maleic anhydride copolymer.
Claim 24
Dependent Claim
16 words
A process according to claim 1 including etching of the bared image-free areas of the support.
Claim 25
Dependent Claim
69 words
A process according to claim 1 in which the developer contains at least one salt of a multi-valent metal selected from the group consisting of chromium, manganese, iron, copper, and the metals of the IInd, IIIrd, and IVth main groups of the Periodic System, said salt reacting with a polymer or a copolymer containing acid groups or anhydride groups which is present in the layer as a resin binder.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-02 | 1981-07-04 | 1982-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-02 | 1985-07-04 | 1986-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-02 | 1989-07-04 | 1990-01-03 | $7700.00 | Window Closed / Lapsed |